/*  $OpenBSD: fnmatch.c,v 1.6 1998/03/19 00:29:59 millert Exp $  */

/*
 * Copyright (c) 1989, 1993, 1994
 *  The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Guido van Rossum.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *  This product includes software developed by the University of
 *  California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)fnmatch.c  8.2 (Berkeley) 4/16/94";
#else
static char rcsid[] = "$OpenBSD: fnmatch.c,v 1.6 1998/03/19 00:29:59 millert Exp $";
#endif
#endif /* LIBC_SCCS and not lint */

/*
 * Function fnmatch() as specified in POSIX 1003.2-1992, section B.6.
 * Compares a filename or pathname to a pattern.
 */

#include <libtar/config.h>

#include <stdio.h>

#ifdef STDC_HEADERS
# include <string.h>
#endif

#ifdef HAVE_CTYPE_H
# include <ctype.h>
#endif

#include <libtar/compat.h>


#define  EOS  '\0'

#define  RANGE_MATCH  1
#define  RANGE_NOMATCH  0
#define  RANGE_ERROR  (-1)

static int rangematch (const char *, char, int, char **);

int
fnmatch(pattern, string, flags)
  const char *pattern, *string;
  int flags;
{
  const char *stringstart;
  char *newp;
  char c, test;

  for (stringstart = string;;)
    switch (c = *pattern++) {
    case EOS:
      if ((flags & FNM_LEADING_DIR) && *string == '/')
        return (0);
      return (*string == EOS ? 0 : FNM_NOMATCH);
    case '?':
      if (*string == EOS)
        return (FNM_NOMATCH);
      if (*string == '/' && (flags & FNM_PATHNAME))
        return (FNM_NOMATCH);
      if (*string == '.' && (flags & FNM_PERIOD) &&
          (string == stringstart ||
          ((flags & FNM_PATHNAME) && *(string - 1) == '/')))
        return (FNM_NOMATCH);
      ++string;
      break;
    case '*':
      c = *pattern;
      /* Collapse multiple stars. */
      while (c == '*')
        c = *++pattern;

      if (*string == '.' && (flags & FNM_PERIOD) &&
          (string == stringstart ||
          ((flags & FNM_PATHNAME) && *(string - 1) == '/')))
        return (FNM_NOMATCH);

      /* Optimize for pattern with * at end or before /. */
      if (c == EOS) {
        if (flags & FNM_PATHNAME)
          return ((flags & FNM_LEADING_DIR) ||
              strchr(string, '/') == NULL ?
              0 : FNM_NOMATCH);
        else
          return (0);
      } else if (c == '/' && (flags & FNM_PATHNAME)) {
        if ((string = strchr(string, '/')) == NULL)
          return (FNM_NOMATCH);
        break;
      }

      /* General case, use recursion. */
      while ((test = *string) != EOS) {
        if (!fnmatch(pattern, string, flags & ~FNM_PERIOD))
          return (0);
        if (test == '/' && (flags & FNM_PATHNAME))
          break;
        ++string;
      }
      return (FNM_NOMATCH);
    case '[':
      if (*string == EOS)
        return (FNM_NOMATCH);
      if (*string == '/' && (flags & FNM_PATHNAME))
        return (FNM_NOMATCH);
      if (*string == '.' && (flags & FNM_PERIOD) &&
          (string == stringstart ||
          ((flags & FNM_PATHNAME) && *(string - 1) == '/')))
        return (FNM_NOMATCH);

      switch (rangematch(pattern, *string, flags, &newp)) {
      case RANGE_ERROR:
        /* not a good range, treat as normal text */
        goto normal;
      case RANGE_MATCH:
        pattern = newp;
        break;
      case RANGE_NOMATCH:
        return (FNM_NOMATCH);
      }
      ++string;
      break;
    case '\\':
      if (!(flags & FNM_NOESCAPE)) {
        if ((c = *pattern++) == EOS) {
          c = '\\';
          --pattern;
        }
      }
      /* FALLTHROUGH */
    default:
    normal:
      if (c != *string && !((flags & FNM_CASEFOLD) &&
         (tolower((unsigned char)c) ==
         tolower((unsigned char)*string))))
        return (FNM_NOMATCH);
      ++string;
      break;
    }
  /* NOTREACHED */
}

static int rangematch(const char *pattern, char test, int flags, char **newp)
{
  int negate, ok;
  char c, c2;

  /*
   * A bracket expression starting with an unquoted circumflex
   * character produces unspecified results (IEEE 1003.2-1992,
   * 3.13.2).  This implementation treats it like '!', for
   * consistency with the regular expression syntax.
   * J.T. Conklin (conklin@ngai.kaleida.com)
   */
  negate = (*pattern == '!' || *pattern == '^');
  if (negate)
    ++pattern;

  if (flags & FNM_CASEFOLD)
    test = tolower((unsigned char)test);

  /*
   * A right bracket shall lose its special meaning and represent
   * itself in a bracket expression if it occurs first in the list.
   * -- POSIX.2 2.8.3.2
   */
  ok = 0;
  c = *pattern++;
  do {
    if (c == '\\' && !(flags & FNM_NOESCAPE))
      c = *pattern++;
    if (c == EOS)
      return (RANGE_ERROR);
    if (c == '/' && (flags & FNM_PATHNAME))
      return (RANGE_NOMATCH);
    if ((flags & FNM_CASEFOLD))
      c = tolower((unsigned char)c);
    if (*pattern == '-'
        && (c2 = *(pattern+1)) != EOS && c2 != ']') {
      pattern += 2;
      if (c2 == '\\' && !(flags & FNM_NOESCAPE))
        c2 = *pattern++;
      if (c2 == EOS)
        return (RANGE_ERROR);
      if (flags & FNM_CASEFOLD)
        c2 = tolower((unsigned char)c2);
      if (c <= test && test <= c2)
        ok = 1;
    } else if (c == test)
      ok = 1;
  } while ((c = *pattern++) != ']');

  *newp = (char *)pattern;
  return (ok == negate ? RANGE_NOMATCH : RANGE_MATCH);
}
